The invention generally relates to medical products and, more particularly, the invention relates to substantially eliminating undesired fluid drawback through a medical valve.
In general terms, medical valving devices often act as a sealed port that may be repeatedly accessed to non-invasively inject fluid into (or withdraw fluid from) a patient's vasculature. Consequently, a medical valve acting as a fluid port permits the patient's vasculature to be freely accessed without requiring such patient's skin be repeatedly pierced by a needle.
More specifically, after it is inserted into a medical valve, a syringe may freely inject or withdraw fluid from the patient. Problems arise, however, when the syringe is withdrawn from the valve. Specifically, a back pressure (i.e., a proximally directed pressure) produced by the withdrawing syringe undesirably can draw blood proximally into the valve or a catheter connected to the valve. In addition to coagulating and impeding the mechanical operation of the valve, blood in the valve also compromises the sterility of the valve and/or catheter.
In accordance with one aspect of the invention, a medical valve having a closed mode and an open mode includes a housing having a proximal end, a distal end, and an interior. The valve also has a valve mechanism within the interior. In illustrative embodiments, the valve mechanism has a gland member and a lifter member. The lifter member moves the gland member toward the proximal end of the housing as the valve transitions from the closed mode to the open mode.
The foregoing and advantages of the invention will be appreciated more fully from the following further description thereof with reference to the accompanying drawings wherein:
In illustrative embodiments of the invention, a valve produces a positive, distally directed pressure (i.e., toward its outlet) when a nozzle or syringe is withdrawn. Such pressure should prevent non-negligible amounts of fluid from s being drawn into the valve at such time. To these ends, the valve has an interior fluid chamber/flow channel sized and configured 1) to expand its volume as the valve transitions toward the open mode, and 2) to reduce its volume as the valve transitions toward the closed mode. Details of this and related embodiments also are discussed below.
When coupled, the housing portions 20 and 22 form the internal chamber 18, which is shaped to comply with the operation of its internal valve element (discussed below). The proximal port 14, which is part of this chamber 18, illustratively is contoured to accept various types of nozzles, such as those complying with ANSI/ISO standards (e.g., luers complying with ANSI and/or ISO standards).
The valve element has a stretchable, resilient, and compressible member (referred to in various embodiments herein as “gland 24”) secured between the inlet housing 18 and outlet housing 20. In illustrative embodiments, the gland 24 is formed from an elastomeric material, such as silicone or rubber. Other materials having similar properties may be used, however, so long as they can perform the functions discussed herein.
The gland 24 has several cooperating sections for controlling fluid flow through the valve 10 while substantially eliminating fluid drawback. Namely, the gland 24 has a proximal section 26 near its proximal end, a distal section 28 near its distal end, and a central section 30 between the proximal and distal sections 26 and 28. The three sections 26, 28, and 30 together form a portion of a contiguous fluid flow path that extends the length of the valve 10. In addition, the gland 24 also has an attachment section 32 for securing the gland 24 within the valve 10 and maintaining fluid flow in the flow channel. In illustrative embodiments, the proximal section 26 of the gland 24 has a slit 33 for providing a low pressure seal.
The valve element also includes a rigid and longitudinally movable cannula 34 secured within the gland 24, and a lifter 36 for urging the gland 24 proximally as the valve 10 transitions from a closed mode to an open mode.
In illustrative embodiments, the cannula 34 is a hollow needle that, together with the gland 24, form a part of the internal flow channel within the valve 10. The cannula 34 is open at its proximal end, closed at its distal end, and has holes 38 in its side just proximal to its distal end. The cannula 34 also has a protruding distal end that facilitates assembly. As shown in the Figures, when in the closed position, the holes 38 are occluded by the gland 24. An annular corner 35 of the interior chamber 18 aids in the sealing the holes 38. In addition, the slit 33 also is normally closed when the valve 10 is in the closed mode.
When the valve 10 is in the fully closed position, the proximal section 26 of the gland 24 is flush with, or extends slightly above, the exterior inlet face of the housing 12 (see, for example,
Insertion of a nozzle (e.g., a luer) into the proximal port 14 forces the gland 24 to move (radially and longitudinally, as discussed below) to an open position. When in that position, a flow channel from the proximal port to the distal port 16 is considered to be formed as follows:
First through the proximal port 14 and the slit 33 in the proximal section 26,
Then through the interior of the gland 24 to the open end of the cannula 34,
Through the cannula channel to the cannula holes 38,
Through a distal hole in the housing 12 to an outlet channel terminating at the distal port 16.
To open this fluid channel, the proximal section 26 of the gland 24 collapses onto the top surface of the cannula 34 to open the slit 33. The cannula 34 also begins traversing distally, thus prying the main body 40 of the lifter 36 radially outwardly. Consequently, the main body 40 of the lifter 36 flexes about the three living hinges 44. This causes the top portion 42 of the lifter 36 to move proximally. Due to their spatial relationship, this lifter movement thus urges the bottom portion of the gland 24 proximally. Accordingly, the overall fluid volume within the flow channel increases.
Removal of the nozzle has a corresponding effect of decreasing the overall flow channel volume. Specifically, as the valve element returns toward the closed position, the gland 24 returns to its relaxed state, which reduces overall internal chamber 18 of volume. As noted above, this volume change should produce a positively directed pressure toward the distal port 16. Such positive pressure consequently should substantially eliminate fluid drawback into the valve 10 or its attached catheter.
It should be noted, however, that the actual volume of the flow channel is anticipated to vary as the valve element moves proximally. In fact, during the return cycle, there could be times when fluid is drawn toward or back into the valve 10 and/or catheter. In illustrative embodiments, however, the overall volume change has a net effect of producing a net positive pressure through the outlet 16, thus substantially eliminating fluid drawback.
In a manner similar to in
Although the above discussion discloses various exemplary embodiments of the invention, it should be apparent that those skilled in the art can make various modifications that will achieve some of the advantages of the invention without departing from the true scope of the invention.
This application is related to the following U.S. patents and U.S. patent applications, the disclosures of which are incorporated herein, in their entireties, by reference: U.S. Pat. No. 6,039,302 (Bromberg & Sunstein LLP attorney docket number 1600/114); U.S. Pat. No. 6,883,778 (Bromberg & Sunstein LLP attorney docket number 1600/121); U.S. Pat. No. 6,755,391 (Bromberg & Sunstein LLP attorney docket number 1600/145); U.S. application Ser. No. 10/224,299 (Bromberg & Sunstein LLP attorney docket number 1600/149); U.S. Pat. No. 6,869,426 (Bromberg & Sunstein LLP attorney docket number 1600/154); U.S. application Ser. No. 10/687,515 (Bromberg & Sunstein LLP attorney docket number 1600/162); and U.S. application Ser. No. 10/700,344 (Bromberg & Sunstein LLP attorney docket number 1600/163). This patent application claims priority from provisional U.S. patent application No. 60/644,068, filed Jan. 14, 2005, entitled, “VALVE WITH INTERNAL LIFTER,” and naming Andrew L. Cote and Brian L Newton as inventors, the disclosure of which is incorporated herein, in its entirety, by reference.
Number | Date | Country | |
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60644068 | Jan 2005 | US |